And here in Switzerland, we have found that clays produce very reactive materials when they're calcined,that's to say heated to around 800 degrees Celsius, significantly lower than the 1,450 needed to produce cement.

在瑞士，我们发现粘土在煅烧时会产生非常活泼的物质， 也就是说， 加热到 800 摄氏度左右，远低于生产水泥所需的 1, 450 摄氏度。